When, where and why to compete.

I am not a competitive person by nature, or usually by practice, but lately I have been feeling the overwhelming compulsion to sign myself up for at least one event, just to see how it goes. I'm not a greenhorn, but I haven't been in enough actual fights, sporting or real, to consider myself "serious". I guess this is what hanging out in a kickboxing/jiu jitsu gym for the last year has done to my mentality. Back in seattle (I was taking JKD) competing never entered my head as I swore to myself it was SD ONLY. I've been sparring a lot lately though and there is this nag in my gut to push it to the next level, if only once. That being said, I want to ask if anyone can recommend organizations in the chicago area to get started in. I'm 140 lbs, 5'7 and 29 years old, if that makes any difference. I have been looking into the IKF as a place to start, but I kind of want to go somewhere where I know there will be a good number of other inexperienced people
I would like to try San Shou, but after reading the rules I thought maybe I should give straight amatuer kickboxing a whirl first. SS seems pretty complicated, but the proposition of throws gets me pumped. Anyway, just looking for some feedback.

Thanks

...and I'm not even gonna ask if I'm too old.